Fears of nuclear annihilation paralyzed the world in the throes of the Cold War. People practiced utterly useless duck-and-cover drills, and paranoid governments invested in expensive underground bunkers. Turns out, an underground nuke would’ve make those bunkers just as effective as hiding under a picnic blanket.

A video of an underground nuclear test surfaced on YouTube on March 25, and it’s putting new perspective on just how powerful nuclear weapons really are.

In the video, a nuclear explosion occurs deep below the surface of the earth, and the land on top of the incinerated explosion zone seemingly melts downward into a giant crater, known as an “underground subsidence crater.”

It’s certainly not as dramatic as the blossoming nuclear mushroom cloud created by standard aerial nuclear testing, but it may be even more intimidating.

Next, see a mind-boggling test photo of the peacekeeper missile, the nuclear weapon so deadly it had to be banned.